Getting Ugly, Dead Bugs, And Going To Manhattan

Getting Ugly, Dead Bugs, And Going To Manhattan

Back in the 1980s I was a budding electronics geek working in a TV repair shop. I spent most of my time lugging TVs to and from customers, but I did get a little bench time in. By then new TVs were entirely solid-state and built on single PC boards, but every once in a while we’d get an old-timer in with a classic hand-wired tube chassis. I recall turning them over, seeing all the caps and resistors soldered between terminal strips bolted to the aluminum chassis and wondering how it could all possibly work. It all looked so chaotic and unkempt compared to the sleek traces and neat machine-inserted components on a spanking new 19″ Zenith with the System 3 chassis. In a word, the old chassis was just – ugly.

Looking back, I probably shouldn’t have been so judgmental. Despite the decades of progress in PCB design and the democratization of board production thanks to KiCad, OSH Park, and the like, it turns out there’s a lot to be said for ugly methods of circuit construction.

Ugly is Beautiful

Construction methods that differ from standard surface-mount and through-hole PCB technology vary, but a decent catch-all term for these methods is “Ugly construction”. Specifics vary, but it’s one of those “You’ll know it when you see it” things. For my money, ugly style is any electronic build technique where the components are not completely mechanically anchored to a substrate, like a clad or unclad board. With through-hole and SMT, we’re used to all the terminals of each component being soldered firmly to the board, making a solid mechanical and electrical connection. Ugly eschews this approach and lets the components all hang out.

Ugly is as Ugly does: A 40-meter receiver. Source
Ugly is as Ugly does: A 40-meter receiver. Source

Sometimes there’s no board at all in an ugly build and the components are just soldered to terminal strips or between input and output connectors. Such builds are not terribly sound mechanically, so they’re mostly reserved for quickie prototypes. When there is a board in an ugly build, it’s generally used solely as a ground plane with only the grounded leads of components soldered down. With ground established and some semblance of mechanical stability added, the other connections are made above the board. Component leads are tied directly together or with short lengths of jumper wire, and eventually the whole circuit starts to come together. Mechanical stability can be added to a joint by running a high-value resistor to ground.

Does Ugly work? You bet! One famous example from the ham radio world is the Ugly Weekender. Designed by Roger and Wes Hayward in 1981, the Ugly Weekender is a low-power (QRP) transmitter for the 40-meter band. Started as a father and son project over Christmas break, the Weekender accomplishes a lot with just a handful of parts tacked to a plain copper-clad board. And Ugly is fast. The “Weekender” part of the UW transmitter refers to the fact that it can be built in a weekend by any reasonably skilled ham with access to a well-stocked parts bin. With no PCB to design, no tedious phototransfer or manual masking process, and no etching, the build can begin right away. I think this is the largest intangible benefit of Ugly construction – it doesn’t interrupt the creative momentum. You get an idea, you start tacking parts down, and you just follow the flow of the design.

There’s a Dead Bug in My Circuit

A bunch of dead-bug TO-92 devices. Source
A bunch of dead-bug TO-92 devices. Source

As you can imagine, Ugly works best for circuits that mostly use discrete components. After all, it’s got to be difficult to tack a 14-pin DIP down to a board, right? Enter the “Dead Bug” style of Ugly. As the name implies, Dead Bug builds have components with all the leads sticking up in the air like a dead bug. Sometimes the DIPs and other components are glued to the board for mechanical stability with a dab of superglue. The important point, though, is that interconnections still all occur above the board, and ground connections are short, direct and many. That huge ground plane is a key feature of Ugly, which is why it’s so often used for RF circuits.

Another benefit of Ugly is the reduction of stray capacitance. Solderless breadboards are great prototyping tools, but there’s no escaping the fact that a grid of long, parallel conductors spaced 0.1″ apart and separated by a dielectric is going to have capacitance. It’s not a lot, and it’s not a factor for every circuit, but a couple of picofarads here and there can add up to a problem. With short leads and no long parallel traces, Ugly minimizes stray capacitance and is another reason a lot of RF circuits use it.

Help for Ugly: Manhattan Style

Ugly only goes so far, though, and it’s not appropriate for every circuit. Ugly tends to be difficult to replicate – after all, when you solder four leads together  in the air and support it with a 10-megohm resistor to ground, it’s a little difficult to document exactly what you did, and even a photograph doesn’t necessarily do it justice. So Ugly sometimes needs some help, and that’s where Manhattan style comes in.

Named after its resemblance to rows of high-rise buildings, Manhattan construction uses small pads punched out of copper-clad board and glued to the ground-plane board. Insulated from the ground-plane, the small copper pads serve as junctions for terminals – no more connections hanging out in mid-air, and no more support resistors. Pads can be punched out or created with a nibbling tool, or even created directly on the backplane board. ICs can be incorporated into Manhattan builds either with tiny pads or with a larger pad with lines scored in the copper by some careful work with a saw. Dead-bugging an IC in a Manhattan build is not out of the question, either.

You might be tempted to think that Manhattan is only useful for through-hole components, but not so fast. With a little ingenuity, even surface-mount components can find their way into Manhattan builds. Following [Paul Harden]’s (NA5N) guide to Manhattan, pads and strips created of the thinner 0.031″ thick copper clad board can be glued to a thicker backplane and used to create landing pads for surface-mount parts. As with any build using SMT, things can get a bit dicey, but with enough pre-planning and the proper tools, Manhattan-SMT can result in some pretty cool builds.

Ugly and Manhattan construction are clearly not suitable for every build, but knowing these techniques can open up some doors and make it a little easier to throw a circuit together. And as [Harry Lythall] (SM0VPO) points out, “The correct construction method is any one that works. The best construction method is the one that works best.” Maybe one of these methods will work best for your next project.

Featured image: [K8IQY]’s SW30+ 30-m CW transceiver. Source.

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